In the design process of a large-size display product such as a television, power of supply tends to be high, the number of output voltages is relatively large, and circuit design is relatively complex. A high-power power board has a complex structure, a large number of sampled signals, and various protective functions, which results in high standby power consumption. A splice plate formed of multiple power boards has not only a complicated circuit, but also a standby power consumption multiple times as large as that of a single power board.
In order to address the problem of too high standby power consumption of circuits caused by the high-power power board and the splice plate, an existing solution is to add contact switches (e.g., relays) to control respective power switches. However, the relays have certain disadvantages in use: when the system enters the working state from the standby state, the relays may produce very loud noises, and it is very likely to produce a spark when contacts thereof get into contact, which is a potential security problem; meanwhile, a relatively large surge current is generated at the moment of power-on, which is prone to causing a false triggering of protective devices, and thus affects user's operation experience.